Regulators May Stymie 60 GHz Use

Emerging 60GHz communications could be a prime example of how a market can be held back by subtle differences in government regulations.

Emerging 60GHz communications could be a prime example of how a market can be held back by subtle differences in government regulations. These discrepancies could impact the speed at which mobile operators are able to roll out high-bandwidth services, holding back the development of markets that depend on high-speed data.

Besides its use in WiFi networks based on the WiGig standard, 60 GHz also has use as a high data rate 4G-backhaul link, replacing expensive fibre optic cables. Engineers are developing phased-array antennas to focus line-of-sight connections using the highly directional 60 GHz signals. Such antennas let operators dynamically steer the links via software, which eases the job of deploying and upgrading connections.

Since FCC regulations for operation at 60 GHz are based on EIRP (equivalent isotropically radiated power) products, developers in the U.S. are pressing ahead with the development of phased-array based backhaul products. Unfortunately regulators in regions such as Europe may force operators to use existing high gain dish-based solutions for 60GHz backhaul, which require time-consuming manual setup and maintenance.

The crux of the issue is that U.S. and European regulators have decided to use different definitions of the radiated power they will allow.

U.S. FCC regulation 15.255 for devices operating in the 60 GHz band specifies EIRP up to a maximum average power levels of +40dBmi. These have also been extended for outdoor use between fixed points to as much as +82dBmi, depending on antenna gain, as the result of an August 2013 ruling by the FCC.

Europe's CEPT REC(09)01, supplemented by ETSI EN 302 217, has a higher standard power level of +55dBmi but typically limits maximum conducted power to +10 dBm and the minimum antenna gain to +30dBi. This approach does not allow the trade-off of antenna gain and power in the way that the more flexible U.S. standard does. Thus equipment will be physically larger, creating aesthetic problems for the design of small cells and increasing installation time due to the need to manually align each link.

In addition, WiGig devices used in small cells outdoors will violate the European standards for minimum antenna gain and maximum conducted power. In addition, European operators who want to deploy point-to-point backhaul links will need to use the combination of high-gain, dish-based antennas and modems that supply less than +10dBm of transmit power. Meanwhile U.S. operators will have the freedom to use modems that supply up to +27dBm of transmit power and make use of steerable, but lower-gain phased-array antennas.

The cost implications of this are huge. US mobile operators can deploy backhaul links based on phased-array technology that, given the economies of scale driven by the high volume WiGig market, can by delivered for less than $1,000. Their counterparts in Europe will be obliged to use traditional dish-based solutions with a typical link currently costing between $5,000 and $8,000.

Unless regulators address the discrepancy in standards, manufacturers of end equipment will be forced to develop two or more sets of products. In addition, operators in Europe will experience higher network rollout costs than their counterparts in North America.

If regulators fail to act, this will be a missed opportunity that puts communications legislation at odds with government objectives to build a digital society as they try to extend the reach of the Internet.

I respect the view of silicon vendors (they better wish to have a single design for all application in the same band).

However, we should not forget that while FCC Part 15 regulation is for "generic radios" (i.e. with no specific spectrum access rights), EC/CEPT regulation is specific for Fixed links systems (having "primary" allocation in the band).

Therefore, while FCC rules are not specifically aimed to maximise the spectrum use for the users, CEPT coexistence study (ECC/REPORTs 113 and 114) are focussed on specific applications and resulted in a balanced regulation maximising (statistically) the availability for both "primary" and "other"users. In particular also for FS users among themselves; it should not be forgotten that EU urban backhauling links will be very short and the O2 absorption becomes of little help in managing interference when high density, multioperator networks are considered.Furthermore, CEPT regulation in most cases are relatively easy to be changed when specific new technology is emerging and its fair compatibility with other users is technically demonstrated.

Anyhow, while the comparison in term of maximum emission limits shows large difference (about 30 dB), the comparison in the practical range of fixed links backhauling technology is significant less important (about 10 dB) and equipment manufactures feeling is that only few more dB power (in the order of 5) would eventually be welcome (possible discussion about ATPC enhance emission might be possible.

At Silicon Image, we fully concur with Mark's observations. In addition to reducing equipment costs, phased array antennas reduce installation and maintenance costs, as the beam can be electronically steered during and after installation without manual intervention. The small size of phased array antennas, combined with the high performance, high integration and low power of CMOS 60GHz RF transceivers also enable wireless mesh networks - the best way to meet the capacity expectations for next generation mobile networks without digging up every street for fiber.